103979-29-9Relevant academic research and scientific papers
Intramolecular photocycloaddition reactions of 2- and 4-(5-arylpent-4-enyl)-1-cyanonaphthalenes
Maeda, Hajime,Enya, Kouhei,Negoro, Naoki,Mizuno, Kazuhiko
, p. 173 - 184 (2019)
Photoreactions of 1-cyanonaphthalene derivatives containing 5-arylpent-4-enyl groups at C-2 or C-4 of the naphthalene ring were investigated. Photoreactions of C-2 derivatives in benzene or CH3CN generated intramolecular [2 + 2] and [3 + 2] photocycloadducts. Substances bearing electron-rich and electron-poor phenyl groups produced respective [2 + 2] and [3 + 2] photocycloadducts preferentially. In contrast, photoreactions of C-4 linked 1-cyanonaphthalenes produced intramolecular [4 + 2] photocycloadducts as main products along with stereoisomers of tricyclic compounds as minor products. The formation of [4 + 2] photocycloadducts was promoted by using benzophenone or Michler's ketone triplet photosensitization, and quenched by O2 or ferrocene. Intramolecular singlet exciplexes, which serve as important intermediates in the mechanistic pathways for these reactions, governed the site-selectivities in photoreactions of both of the 2- and 4-(5-arylpent-4-enyl)-1-cyanonaphthalenes. In addition, [4 + 2] photocycloadducts were observed to undergo di-π-methane rearrangement under irradiation conditions to produce angular triquinane derivatives.
Lanthanide-Catalyzed Tandem Addition of Amines to Cyanoalkenes: Synthesis of Cyclic Amidines
Hou, Jinsong,Yang, Gaosheng,Chai, Zhuo
supporting information, p. 453 - 463 (2022/01/04)
A tandem insertion of aliphatic nitriles and unactivated alkenes to the N-H bond of secondary aliphatic amines catalyzed by simple trialkyl rare-earth metal complexes was disclosed. This reaction provides a highly atom-economic and stereoselective way to a range of cyclic amidines under mild reaction conditions.
Nickel-Catalysed Allylboration of Aldehydes
Dennis, Francesca M.,Partridge, Benjamin M.,Robertson, Craig C.
, p. 1903 - 1914 (2020/07/04)
A nickel catalyst for the allylboration of aldehydes is reported, facilitating the preparation of homoallylic alcohols in high diastereoselectivity. The observed diastereoselectivities and NMR experiments suggest that allylation occurs through a well-defined six-membered transition state, with nickel acting as a Lewis acid.
Copper-Catalyzed Enantioselective Allylic Alkylation with a γ-Butyrolactone-Derived Silyl Ketene Acetal
Jette, Carina I.,Tong, Z. Jaron,Hadt, Ryan G.,Stoltz, Brian M.
supporting information, p. 2033 - 2038 (2020/01/02)
Herein, we report a Cu-catalyzed enantioselective allylic alkylation using a γ-butyrolactone-derived silyl ketene acetal. Critical to the development of this work was the identification of a novel mono-picolinamide ligand with the appropriate steric and electronic properties to afford the desired products in high yield (up to 96 %) and high ee (up to 95 %). Aryl, aliphatic, and unsubstituted allylic chlorides bearing a broad range of functionality are well-tolerated. Spectroscopic studies reveal that a CuI species is likely the active catalyst, and DFT calculations suggest ligand sterics play an important role in determining Cu coordination and thus catalyst geometry.
Photocatalyzed Diastereoselective Isomerization of Cinnamyl Chlorides to Cyclopropanes
Dykstra, Ryan,Gutierrez, Osvaldo,Martin, Robert T.,Tambar, Uttam K.,Troian-Gautier, Ludovic,Xu, Bin
supporting information, p. 6206 - 6215 (2020/04/27)
Endergonic isomerizations are thermodynamically unfavored processes that are difficult to realize under thermal conditions. We report a photocatalytic and diastereoselective isomerization of acyclic cinnamyl chlorides to strained cyclopropanes. Quantum mechanical calculations (uM06-2X and DLPNO), including TD-DFT calculations, and experimental studies provide evidence for the energy transfer from an iridium photocatalyst to the allylic chloride substrate followed by C-Cl homolytic cleavage. Subsequent Cla￠ radical migration forms a localized triplet 1,3-diradical intermediate that, after intersystem crossing, undergoes ring-closing to form the desired product. The mild reaction conditions are compatible with a broad range of functional groups to generate chlorocyclopropanes in high yields and diastereoselectivities. A more efficient process is developed by addition of a catalytic amount of a nickel complex, and we propose a novel role for this cocatalyst to recycle an allyl chloride byproduct generated in the course of the reaction. The reaction is also shown to be stereoconvergent, as an E/Z mixture of cinnamyl chlorides furnish the anti-chlorocyclopropane product in high diastereoselectivity. We anticipate that the use of a visible light activated photocatalyst to transform substrates in combination with a transition metal catalyst to recycle byproducts back into the catalytic cycle will provide unique opportunities for the discovery of new reactivity.
PdII/Novel Chiral Cinchona Alkaloid Oxazoline-Catalyzed Enantioselective Oxidative Cyclization of Aromatic Alkenyl Amides
Tian, Qinqin,Liu, Yulong,Wang, Xiaoyun,Wang, Xie,He, Wei
, p. 3850 - 3855 (2019/06/08)
A highly enantioselective PdII-catalyzed aza-Wacker oxidation tandem cyclization of aromatic nitrogen-containing dienes has been achieved in the presence of novel chiral cinchona alkaloid oxazoline ligands for the first time, affording chiral dihydroindole nitrogen-containing polycyclic compounds with good yields (up to 83 %), high diastereoselectivities (> 95:5 dr), and excellent enantioselectivities (up to 97 % ee).
A Convenient Palladium-Catalyzed Carbonylative Synthesis of (E)-3-Benzylidenechroman-4-ones
Wang, Wei-Feng,Peng, Jin-Bao,Qi, Xinxin,Ying, Jun,Wu, Xiao-Feng
supporting information, p. 3521 - 3524 (2019/02/14)
A convenient palladium-catalyzed carbonylation reaction for the efficient synthesis of (E)-3-benzylidenechroman-4-ones has been developed. Using TFBen as a solid CO source, a range of substituted (E)-3-benzylidenechroman-4-ones were prepared in moderate to good yields with 2-iodophenols and allyl chlorides as the substrates. Additionally, substituted quinolin-4(1H)-ones can also be obtained with 2-iodoaniline as the starting material.
Rhodium(ii)-catalyzed intramolecular formal [4 + 3] cycloadditions of dienyltriazoles: Rapid access to fused 2,5-dihydroazepines
Tian, Yu,Wang, Yuanhao,Shang, Hai,Xu, Xudong,Tang, Yefeng
supporting information, p. 612 - 619 (2015/02/05)
Rhodium(ii)-catalyzed intramolecular [4 + 3] cycloadditions of dienyltriazoles have been developed, which enable the efficient synthesis of various fused 2,5-dihydroazepines. Mechanistically, the titled reaction proceeds via an interesting tandem cyclopropanation/aza-cope rearrangement.
Multifunctional novel Diallyl disulfide (DADS) derivatives with β-amyloid-reducing, cholinergic, antioxidant and metal chelating properties for the treatment of Alzheimer's disease
Manral, Apra,Saini, Vikas,Meena, Poonam,Tiwari, Manisha
, p. 6389 - 6403 (2015/10/05)
A series of novel Diallyl disulfide (DADS) derivatives were designed, synthesized and evaluated as chemical agents, which target and modulate multiple facets of Alzheimer's disease (AD). The results showed that the target compounds 5a-l and 7e-m exhibited significant anti-Aβ aggregation activity, considerable acetylcholinesterase (AChE) inhibition, high selectivity towards AChE over butyrylcholinesterase (BuChE), potential antioxidant and metal chelating activities. Specifically, compounds 7k and 7l exhibited highest potency towards self-induced Aβ aggregation (74% and 71.4%, 25 μM) and metal chelating ability. Furthermore, compounds 7k and 7l disaggregated Aβ fibrils generated by Cu2+-induced Aβ aggregation by 80.9% and 78.5%, later confirmed by transmission electron microscope (TEM) analysis. Besides, 7k and 7l had the strongest AChE inhibitory activity with IC50 values of 0.056 μM and 0.121 μM, respectively. Furthermore, molecular modelling studies showed that these compounds were capable of binding simultaneously to catalytic active site (CAS) and peripheral anionic site (PAS) of AChE. All the target compounds displayed moderate to excellent antioxidant activity with ORAC-FL values in the range 0.546-5.86 Trolox equivalents. In addition, absorption, distribution, metabolism and excretion (ADME) profile and toxicity prediction (TOPKAT) of best compounds 7k and 7l revealed that they have drug like properties and possess very low toxic effects. Collectively, the results strongly support our assertion that these compounds could provide good templates for developing new multifunctional agents for AD treatment.
Congested C-C bonds by Pd-catalyzed enantioselective allyl-allyl cross-coupling, a mechanism-guided solution
Ardolino, Michael J.,Morken, James P.
supporting information, p. 7092 - 7100 (2014/06/09)
Under the influence of a chiral bidentate diphosphine ligand, the Pd-catalyzed asymmetric cross-coupling of allylboron reagents and allylic electrophiles establishes 1,5-dienes with adjacent stereocenters in high regio-and stereoselectivity. A mechanistic study of the coupling utilizing reaction calorimetry and density functional theory analysis suggests that the reaction operates through an inner-sphere 3,3′-reductive elimination pathway, which is both rate-defining and stereodefining. Coupled with optimized reaction conditions, this mechanistic detail is used to expand the scope of allyl-allyl couplings to allow the generation of 1,5-dienes with tertiary centers adjacent to quaternary centers as well as a unique set of cyclic structures.
